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(11) | EP 3 187 417 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | AIR CONDITIONING SYSTEM |
| (57) The invention provides an air conditioning system (1) for a cabin (10), comprising
a pressurized air source (2), a cooling air source (3), a main heat exchanger (4),
a compressor (5), a manifold (6) and a mixing chamber (7). The inlet (43) of the cold
side of the main heat exchanger (4) is in fluid communication with the cooling air
source (3), and the inlet (41) of the hot side of the main heat exchanger (4) is in
fluid communication with the pressurized air source (2). The inlet (51) of the compressor
is in fluid communication with the outlet (44) of the cold side of the main heat exchanger
(4).
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention is related to the field of aircraft engines, in particular to the field of cooling systems.
BACKGROUND OF THE INVENTION
[0002] The cabin of a modern passenger aircraft is air-conditioned usually both when the aircraft is flying and is on the ground by means of the aircraft's own air conditioning system. The aircraft air conditioning system is supplied with pressurized bleed air which is taken from an engine compressor or Auxiliary Power Unit compressor.
[0003] Typically, this air passes through a so called "air cycle machine" that comprises, among others, one or several heat exchangers, compressor and one or several turbines in order to cool it to a desired low temperature and pressure, . For the working of this kind of air conditioning system in the state of art, this air exiting the air cycle machine, that usually follows or acts performing an inverse Brighton cycle, is usually mixed in a mixing chamber with air recirculated from the cabin and exits in different pipes. These pipes exiting the mixing chamber may receive air at different temperatures from a manifold, in such a way that they blow air into the cabin at different temperatures.
SUMMARY OF THE INVENTION
[0004] The present invention takes the air that already entered in the ram air channel that uses that air for cooling down the temperature in the heat exchangers of the air cycle machine to be compressed and used later on to feed the cabin either via mixing chambers or via an air temperature manifold, since this temperature will be higher than the one selected for the cabin. In this manner the drag is reduced as well as the power needed in the overall cycle, which is improved and therefore achieving lower fuel consumption.
[0005] Thus, the present invention provides an air conditioning system according to claim 1 and an aircraft according to claim 13 as an alternative solution to the aforementioned problems. All the features described in this specification, including the claims, description and drawings, can be combined in any way, except for the cases of mutually exclusive features. The dependent claims define preferred embodiments of the invention.
[0006] According to a first aspect, the invention provides an air conditioning system for a cabin of an aircraft, the air conditioning system comprising:
a pressurized air source which, when in its operative mode, provides work air with a pressure higher than 100 kPa;
a cooling air source, suitable for providing cooling air;
a main heat exchanger with a cold side and a hot side, the hot side comprising an inlet and an outlet and the cold side comprising an inlet and an outlet, in such a way that the inlet of the cold side of the main heat exchanger is in fluid communication with the cooling air source, and the inlet of the hot side of the main heat exchanger is in fluid communication with the pressurized air source;
a secondary duct which bleeds part of the air, from the outlet of the cold side of the main heat exchanger, or from the inlet of the cold side of the main heat exchanger;
a first valve configured to allow or restrict the pass of air bled to the secondary duct; and
a compressor with an inlet and an outlet, the inlet of the compressor being located in fluid communication with, the outlet of the cold side of the main heat exchanger or the inlet of the cold side of the main heat exchanger, a second valve being located in fluid communication with the outlet of the compressor; wherein the outlet of the compressor is in fluid communication with mixing means which in turn are in fluid communication with the cabin.
[0007] This air conditioning system allows using less air from the air pressurized source than the air conditioning systems known in the state of the art, since part of the air obtained from the atmosphere by the cooling air source is conveniently treated and added to the air to be introduced in the cabin.
[0008] In a particular embodiment, mixing means comprise,
a manifold, comprising at least one inlet and at least one outlet, wherein at least one inlet of the manifold is in fluid communication with the outlet of the compressor, each inlet of the manifold comprising a third valve;
a mixing chamber comprising at least one inlet and at least one outlet, one of the inlets of the mixing chamber being fed by the outlet of the hot side of the main heat exchanger, and the at least one outlet of the mixing chamber being in fluid communication with the cabin;
wherein at least an outlet of the manifold is in fluid communication with an outlet of the mixing chamber, this outlet of the manifold comprising a fourth valve; and wherein each outlet of the mixing chamber is in fluid communication with the cabin.[0009] In a particular embodiment, mixing means comprise
a manifold, comprising at least one inlet and at least one outlet, wherein at least one inlet of the manifold is in fluid communication with the outlet of the compressor, each inlet of the manifold comprising a third valve;
a mixing chamber comprising at least two inlets and a plurality of outlets, one of the inlets of the mixing chamber being fed by the outlet of the hot side of the main heat exchanger, one of the inlets of the mixing chamber being fed by the and the plurality of outlets of the mixing chamber being in fluid communication with the cabin;
wherein at least an outlet of the manifold is in fluid communication with an outlet of the mixing chamber, this outlet of the manifold comprising a fourth valve; and wherein each outlet of the mixing chamber is in fluid communication with the cabin.[0010] In a particular embodiment, the air conditioning system further comprises a bypass channel which puts the pressurized air source in fluid communication with the manifold and a fifth valve configured to allow or restrict the pass of air bled to the bypass channel.
[0011] In a particular embodiment, mixing means comprise a mixing chamber comprising at least two inlets and a plurality of outlets, one of the inlets of the mixing chamber being fed by the outlet of the hot side of the main heat exchanger, one of the inlets of the mixing chamber being fed by the and the plurality of outlets of the mixing chamber being in fluid communication with the cabin.
[0012] These air conditioning systems have a better control of air temperature which is intended to be introduced in the cabin, as different temperatures may be obtained by the suitable setting of the outlets of the mixing chamber.
[0013] In a particular embodiment, the air conditioning system further comprises a secondary heat exchanger by means of which heat is transferred from the outlet of the compressor to the air in the secondary duct.
[0014] In a particular embodiment, the air conditioning system further comprises a turbine with an inlet and an outlet, the inlet of the turbine being in fluid communication with an outlet of the cabin, wherein the compressor is driven by energy produced in the turbine.
[0015] This air conditioning system demands lower energy consumption, as the compressor does not need an external energy source to be moved.
[0016] In a particular embodiment, the air conditioning system further comprises a secondary heat exchanger by means of which heat is transferred from the outlet of the cabin to the air in the secondary duct.
[0017] In a particular embodiment, at least a second outlet of the manifold is in fluid connection with a second outlet of the mixing chamber.
[0019] In a second inventive aspect, the invention provides an aircraft comprising an air conditioning system according to any embodiment of the first inventive aspect.
DESCRIPTION OF THE DRAWINGS
[0020] These and other characteristics and advantages of the invention will be clearly understood in view of the detailed description of the invention and further in view of the preferred embodiments of the invention, with reference to the drawings. Preferred embodiments are given just as examples and are not intended to limit the scope of the present invention.
- Figure 1
- This figure shows a side view of a first embodiment of an air conditioning system according to the invention.
- Figure 2
- This figure shows a side view of a second embodiment of an air conditioning system according to the invention.
- Figure 3
- This figure shows a side view of a third embodiment of an air conditioning system according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Having outlined the object of the invention, specific non-limitative embodiments are described hereinafter.
[0022] Figure 1 shows a particular embodiment of an air conditioning system according to the invention.
[0023] This figure shows an air conditioning system (1) for a cabin (10) of an aircraft, the air conditioning system (1) comprising:
a pressurized air source (2) which, when in its operative mode, provides work air with a pressure higher than 100 kPa;
a cooling air source (3), suitable for providing cooling air;
a main heat exchanger (4) with a cold side and a hot side, the hot side comprising an inlet (41) and an outlet (42) and the cold side comprising an inlet (43) and an outlet (44), the main heat exchanger being included in an air cycling machine (15);
a compressor (5) with an inlet (51) and an outlet (52), a second valve (31) being located in fluid communication with the outlet (52) of the compressor;
a mixing chamber (7) comprising an inlet (71) and two outlets (72, 73).
[0024] The inlet (43) of the cold side of the main heat exchanger (4) is in fluid communication with the cooling air source (3), and the inlet (41) of the hot side of the main heat exchanger (4) is in fluid communication with the pressurized air source (2). The main heat exchanger (4) thus allow a heat exchanging between the cooling air obtained in the cooling air source (3) and the work air obtained in the pressurized air source (2).
[0025] The inlet (51) of the compressor is located in fluid communication with the outlet (44) of the cold side of the main heat exchanger (4), so that the cooling air exiting the main heat exchanger (4) enters the compressor (5).
[0026] In a particular embodiment, the compressor (5) is moved by the energy provided by an electric motor (99).
[0027] In a further particular embodiment (not shown in the figures), the compressor (5) is moved by the energy provided by the air cycling machine (15).
[0028] This air conditioning system (1) comprises a secondary duct (13) which bleeds part of the air from the outlet (44) of the cold side of the main heat exchanger (4), wherein the air conditioning system (1) further comprises a first valve (11) configured to allow or restrict the pass of air bled to the secondary duct (13).
[0029] This air conditioning system (1) further comprises a secondary heat exchanger (8). This secondary heat exchanger (8) is used to transfer heat from the outlet (52) of the compressor (5) to the air exiting the cold side of the main heat exchanger (4).
[0030] In this embodiment, the air conditioning system (1) further comprises a bypass channel (14) which puts the pressurized air source (2) in fluid communication with the manifold (6) and a fifth valve (12) configured to allow or restrict the pass of air bled to the bypass channel (14).
[0031] In this embodiment, the air conditioning system (1) further comprises a manifold (6), comprising two inlets (61, 62) and two outlets (63, 64), wherein the two inlets (61, 62) of the manifold (6) are in fluid communication with the outlet (52) of the compressor, the second valve (31) being located between the two inlets (61, 62) of the manifold (6) and the outlet (52) of the compressor. Each inlet (61, 62) of the manifold (6) comprises a third valve (32, 33) and each outlet (63, 64) of the manifold (6) comprises a fourth valve (34, 35).
[0032] Each outlet (63, 64) of the manifold (6) is in fluid communication with an outlet (72, 73) of the mixing chamber (7) and each outlet (72, 73) of the mixing chamber (7) is in fluid communication with the cabin (10). Outlets (63, 64) of the manifold are used to control the final temperature obtained in the different outlets (72, 73) of the mixing chamber (7). By feeding each outlet (72, 73) of the mixing chamber (7) with one outlet (63, 64) of the manifold (6) which is at different temperature, different temperatures are obtained in each of the outlets (72, 73) of the mixing chamber (7). In other embodiments, the manifold (6) comprises more outlets.
[0033] Figure 2 shows another embodiment of an air conditioning system (1) according to the invention.
[0034] This embodiment does not comprise a bypass channel, and it does not comprise a manifold either.
[0035] Air enters and exits the cabin (10) so that it is renewed and conditioned. In consequence, the cabin comprises inlets and one outlet (101). In this embodiment, the outlet (101) of the cabin comprises a sixth valve (16).
[0036] In this particular embodiment, the compressor (5) is moved by means of a turbine (9). This turbine (9) comprises an inlet (91) and an outlet (92). The inlet (91) of the turbine is in fluid communication with the outlet (101) of the cabin (10), so it is fed by air exiting the cabin (10). In this embodiment, energy contained in the air exiting from the cabin is used to move the turbine (9) so that no more energy sources are used, thus saving more energy consumption in the air conditioning system of this embodiment. In other embodiments, this turbine (9) is moved by means of air exiting the main heat exchanger (4) or by any other means. A third heat exchanger (81) is placed such that heat is transferred between the inlet of the turbine (91) and the exit of the compressor (52). A one way valve (36) is placed in the inlet of the turbine (91).
[0037] In this embodiment, the outlet (52) of the compressor is in fluid communication with an inlet (74) of the mixing chamber. The other inlet (71) of the mixing chamber (7) is fed by the outlet (42) of the hot side of the main heat exchanger (4), and the outlets (72, 73) of the mixing chamber are in fluid communication with the cabin (10).
[0038] Because of this arrangement, fresh air coming from the cooling air source (3) is available to be part of the temperature control, and part of it may be introduced in the mixing chamber (7).
[0039] Figure 3 shows another embodiment of an air conditioning system (1) according to the invention.
[0040] This air conditioning system (1) is similar to the one shown in Figure 1, but the outlet (52) of the compressor (5) is in fluid communication with both an inlet (74) of the mixing chamber and with an inlet (61) of the manifold (6). There is a seventh valve (37) in the inlet (74) of the mixing chamber (7) to control this flow between the outlet (52) of the compressor (5) and the inlet (74) of the mixing chamber (7).
a pressurized air source (2) which, when in its operative mode, provides work air with a pressure higher than 100 kPa;
a cooling air source (3), suitable for providing cooling air;
a main heat exchanger (4) with a cold side and a hot side, the hot side comprising an inlet (41) and an outlet (42) and the cold side comprising an inlet (43) and an outlet (44), in such a way that the inlet (43) of the cold side of the main heat exchanger (4) is in fluid communication with the cooling air source (3), and the inlet (41) of the hot side of the main heat exchanger (4) is in fluid communication with the pressurized air source (2);
a secondary duct (13) which bleeds part of the air, from the outlet (44) of the cold side of the main heat exchanger (4); or from the inlet (43) of the cold side of the main heat exchanger (4),
a first valve (11) configured to allow or restrict the pass of air bled to the secondary duct (13); and
a compressor (5) with an inlet (51) and an outlet (52), the inlet (51) of the compressor being located in fluid communication with, the outlet (44) of the cold side of the main heat exchanger (4) or the inlet (43) of the cold side of the main heat exchanger (4), a second valve (31) being located in fluid communication with the outlet (52) of the compressor;
wherein the outlet (52) of the compressor is in fluid communication with mixing means which in turn are in fluid communication with the cabin (10).a manifold (6), comprising at least one inlet (61, 62) and at least one outlet (63, 64), wherein at least one inlet (61) of the manifold (6) is in fluid communication with the outlet (52) of the compressor, each inlet (61, 62) of the manifold (6) comprising a third valve (32, 33);
a mixing chamber (7) comprising at least one inlet (71) and at least one outlet (72, 73), one of the inlets (71) of the mixing chamber (7) being fed by the outlet (42) of the hot side of the main heat exchanger (4), and the at least one outlet (72, 73) of the mixing chamber being in fluid communication with the cabin (10);
wherein at least an outlet (63, 64) of the manifold (6) is in fluid communication with an outlet (72, 73) of the mixing chamber (7), this outlet (63, 64) of the manifold (6) comprising a fourth valve (34, 35);and wherein each outlet (72, 73) of the mixing chamber (7) is in fluid communication with the cabin (10).
a manifold (6), comprising at least one inlet (61, 62) and at least one outlet (63, 64), wherein at least one inlet (61) of the manifold (6) is in fluid communication with the outlet (52) of the compressor, each inlet (61, 62) of the manifold (6) comprising a third valve (32, 33);
a mixing chamber (7) comprising at least two inlets (71, 74) and a plurality of outlets (72, 73), one of the inlets (71) of the mixing chamber (7) being fed by the outlet (42) of the hot side of the main heat exchanger (4), one of the inlets (74) of the mixing chamber (7) being fed by the and the plurality of outlets (72, 73) of the mixing chamber being in fluid communication with the cabin (10);
wherein at least an outlet (63, 64) of the manifold (6) is in fluid communication with an outlet (72, 73) of the mixing chamber (7), this outlet (63, 64) of the manifold (6) comprising a fourth valve (34, 35);
and wherein each outlet (72, 73) of the mixing chamber (7) is in fluid communication with the cabin (10).